Hioki CT6841 20A AC/DC Current Probe

Key Features At A Glance

• CT6841 rated 20A AC/DC and CT6843 rated 200A AC/DC — choose the tier matching your measurement range
• Clamp-on design measures AC/DC current without cutting or disconnecting the conductor
• Frequency band from DC to 500kHz (CT6843) up to DC to 1MHz (CT6841) across the series
• Basic amplitude accuracy of ±0.3% rdg. with ±0.1 deg phase accuracy
• Operating temperature range of -40°C to 85°C for environmental and engine-compartment testing
• Flux-gate sensing minimizes offset drift for stable long-term DC measurement
• Compact sensor head allows single-handed operation with a robust locking mechanism
• Compatible with the Power Analyzer 3390
• Measurable conductor diameter of φ20 mm (0.79") or less

The CT6841 and CT6843 are clamp-on AC/DC current probes that sense current by clamping around a conductor, removing the need to cut or disconnect the wire being measured. Both pair high-accuracy measurement with a compact form: a smaller sensor head and grip make single-handed operation easy, and a robust locking mechanism keeps the sensor on the wire even when subjected to external shock. They are offered as replacements for the legacy Universal Clamp On CT 9277/9278, delivering improved amplitude accuracy and broader frequency characteristics relative to those earlier models.

These current probes are intended for power-measurement work. They are used to measure the charge and discharge efficiency of EV and HEV batteries, where the clamp-type design enables high-accuracy measurement on wiring that cannot easily be disconnected and the heat-resistant resin casing allows measurements inside engine compartments. They also support evaluation of inverter and power conditioner efficiency and the evaluation of fuel cells, contactless power supply circuitry, and other next-generation devices. Because amplitude and phase accuracy both matter when measuring AC power — with phase accuracy having a particularly large effect when the power factor is low — the high phase accuracy of these sensors helps ensure accurate power measurement.

ValueTronics stocks and holds its own inventory in a 20,000 square-foot secure warehouse at 1675 Cambridge Drive in Elgin, Illinois.

Compare Other Models in This Series

The CT6841 and CT6843 form a two-model family of clamp-on AC/DC current probes that share the same compact, single-handed form factor, the same -40°C to 85°C operating temperature range, and the same ±0.3% rdg. basic amplitude accuracy. Both use flux-gate sensing for zero-point stability and clamp around a conductor of φ20 mm or less, so neither requires cutting or disconnecting the wire under test.

Within that shared design, the two models are separated primarily by current capacity and frequency band, letting a buyer select the probe that matches the current level and signal bandwidth of the circuit being evaluated.

Each model below is its own dedicated product page with condition-matched pricing for the new unit. Select the model that fits your measurement requirements, then choose the listing that matches the condition and price you need.

The CT6841 is rated for 20A AC/DC with a frequency band of DC to 1MHz and an output of 0.1V/A, accepting a maximum input current of 40A rms (57A peak). The CT6843 is rated for 200A AC/DC with a frequency band of DC to 500kHz and an output of 0.01V/A, accepting a maximum input current of 400A rms (570A peak). The CT6841 weighs approximately 350 g and the CT6843 approximately 370 g.

These differences map directly to application fit: the CT6841 reaches the higher DC to 1MHz band at the lower 20A rating, while the CT6843 trades band for the higher 200A current capacity. The comparison table that follows lists the per-model values — rated current, frequency characteristics, output voltage, maximum input, and power consumption — side by side.

Additional differences in specifications beyond the few shown above are not listed here — see each model's full specifications below.

Accessories Supplied

• Instruction manual
• Mark band (6)
• Carrying Case

Replaces: per the manufacturer, this model replaces 9277, 9278.

Product Core & Specifications

Important: Standalone current-probe use requires a separate power supply.

Important: Maximum input current is based on the derating characteristics graph.

Important: DC accuracy depends on the level of offset adjustment.

Recommended pairing: connect the CT6841/CT6843 directly to the Power Analyzer 3390, or to an oscilloscope or Memory HiCorder via Connection Cord L9217 and Sensor Unit 9555-10.

About this New unit

This is a brand-new, factory-sealed unit, supplied exactly as it arrives from the manufacturer and backed by the full manufacturer warranty. For the exact configuration, available options, included accessories, or current lead time for your application, our Test Architects can confirm the details before you order.

ValueTronics supplies both new and used test and measurement equipment. New units ship factory-sealed, exactly as received from the manufacturer; every used unit is inspected and functionally verified in-house at our 20,000 sq ft secure facility in Elgin, Illinois before it ships. Our Test Architects can help you select the condition, calibration, and configuration that fit your application.

Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.